Electronic equipment racks are generally designed to receive a number of electronic components arranged vertically in the rack, mounted on shelves, and/or to front and rear mounting rails. The electronic equipment may include, for example, printed circuit boards, communications equipment, computers, including computer servers, or other electronic components.
Electronic equipment housed in racks produces a considerable amount of heat, which undesirably affects performance and reliability of the electronic equipment. Often the heat produced by the rack-mounted components is not evenly distributed in the racks. Inadequate supply of cool air and hot air recirculation can reduce equipment reliability substantially and can cause other performance problems. Accordingly, rack-mounted computer systems typically require effective cooling systems to maintain operational efficiency. Cooling can be accomplished by introducing cooled air into an equipment rack and causing the air to flow through equipment in the rack to remove some or all of the heat. The air exits the rack at an increased temperature.
A conventional solution for cooling racks of electronic equipment is to position the equipment racks in rows on a raised floor in a hot aisle and cold aisle configuration, with the fronts of the equipment racks in one row facing the fronts of the equipment racks in an adjacent row. Air cooled by a central air conditioning system is ducted under the raised floor, and perforated or vented floor tiles are provided in the cold aisles to release chilled air towards the fronts of the equipment racks. Chilled air is then drawn into the equipment mounted in the rack and heated air is exhausted out the back of each rack into the hot aisle.
Unfortunately, as technology has rapidly progressed to ever smaller computer chips used to perform more tasks at faster rates the heat produced by such has increased exponentially. The perforated tiles used to deliver air from the subfloor into the room's ambient air can only direct it straight up causing the need for the servers in the cabinets to pull air in a horizontal direction while the natural air flow is in a vertical motion sometimes flowing at a rate of 1000 CFM. However, this process does not work in an efficient manner given the new heat loads encountered in modern data centers.
The rate of actual usage of airflow into the server cabinets as evaluated by floor manufacturing companies ranges from as low as 30% of all air produced in the data centers. This is not to mention that the servers exhaust fans have heat sync's that cause them to ramp up in speed thus using more energy because of the lack of cooling they are receiving from the supply. Studies have been performed to show how even turning up the set point on the air handlers to try to save energy has caused these server fans to use as much energy as the owner thought they were saving by making these changes.
Thus, what is needed is an apparatus and method for delivering a cooling air to the data center racks in an energy efficient manner to meet the needs of ever increasing heat loads.